"It is 1942, and at the new Kent military hospital Heron's Park, postman Joseph Higgins delivers seven letters of acceptance for infirmary roles. He has no idea that one of the recipients will later cause his demise. When Higgins returns to Heron's Park with injuries from a bombing raid in 1943, his inexplicable death in the operating theatre casts four nurses and three doctors under suspicion, and a second, sudden death brings Inspector Cockrill to the hospital. As an air raid detains the inspector for the night, the stage is set for a tense and claustrophobic investigation with a close-knit cast of suspects in this golden age masterclass of red herrings and tricky twists"--